1) Standard Oxygen Transfer Rate (SOTR) – Pounds of oxygen transferred to water per hour (lbs O2 /hour). SOTR is measured in clean water when the dissolved oxygen (DO) concentration is zero at all points in the water volume, the water temperature is 20o C, and the barometric pressure is 1.00 atm (101kPa)
2) Standard Aeration Efficiency (SAE) – Standard Oxygen Transfer Rate per unit total power input. SAE is typically expressed as the pounds of oxygen transferred to the water per hour per HP (lbs O2 /hour/HPwire), and is sometimes referred to as SAE Wire. SAE is used as a measure of how efficiently an aerator is transferring oxygen.